External Repositories

An external repository lets you access a local repository from another Tenable Security Center deployment for reporting purposes. External repository data is read-only. You cannot use an external repository as the Import Repository for active scans. Tenable Security Center supports two types of external repositories:

  • Offline repositories allow you to share repository data from one Tenable Security Center deployment to your primary Tenable Security Center deployment via manual export and import (a .tar.gz archive file).

  • Remote repositories allow you to share repository data from one Tenable Security Center deployment to your primary Tenable Security Center deployment via an SSH session. By default, Tenable Security Center uses ECDSA keys for remote repository authentication.

About Offline and Remote Repositories

Task Offline Repository Remote Repository
Data transfer Manual — export a .tar.gz archive from one deployment and import it to the other. Automatic — Tenable Security Center syncs data over SSH on a configured schedule.
Typical use case Air-gapped deployments with no network path between instances. For more information, see Considerations for Air-Gapped Environments. Networked deployments where both instances can communicate over SSH. For large enterprise deployments, see Tiered Remote Repositories.
Version requirement None. Both Tenable Security Center deployments must run the same version.
Data freshness Updated manually each time you export and import. Updated automatically on the configured schedule.
Key limitation Each import overwrites previously imported data. You cannot combine data from multiple export files in a single offline repository. Both deployments must be reachable over SSH. Requires an ed25519 SSH key for authorization (see Caution below).

Caution: Tenable Security Center 6.8 uses an updated SSH library. When you update to Tenable Security Center 6.8 or later, you must add an ed25519 key for authorization to successfully sync remote repositories. If you do not add the new key, synchronization of your remote repositories will fail.

Configure an Offline Repository

To fully configure an offline repository:

  1. Add an offline repository to your primary Tenable Security Center deployment.
  2. Export a repository from your other Tenable Security Center deployment.
  3. Import the repository to the offline repository on your primary Tenable Security Center deployment.

Configure a Remote Repository

To fully configure a remote repository:

  1. Add a remote repository to your primary Tenable Security Center deployment, specifying the IP address of the remote instance.
  2. When prompted, provide credentials for an administrator account on the remote Tenable Security Center. The deployments exchange SSH keys and the available repositories populate automatically.
  3. Select the repository to sync and configure the update schedule.

For more information, see Offline Repository Options, Remote Repositories, Repositories, and Add a Repository.